Abstract: Through the perspective of the sources of law, we find that the relationship between the state law and the folk law is particularly close. Before modern times, the state law in many countries was entirely a collection of folk laws. Since modern times, although legislative techniques, levels of specialization, organization of the legislative body have been improving all the time, folk law is still recognized by state law to a certain degree. The state law and folk law have coexisted in homogeneous and symbiotic culture soils. They share the common value in the pursuit of harmonious social orders. Therefore, only if we have a rational understanding of their relationship, can we serve China's legislation and judicial practices better.